Spreading properties of high polymers

Abstract

Many linear polymers containing water‐attracting groups spread uniformly at the airwater interface. The spreading property of polymethyl methacrylate is due to the ester groups which serve as anchors and promote spreading. The spreading of polystyrene, although it is a pure hydrocarbon, appears probably to be due to the end groups in each polymer molecule, introduced at the termination of the chains which act as anchors and facilitate spreading. The surface pressure extended by the films of the high polymers is a sort of two‐dimensional swelling pressure. The distinguishing feature of these films is their high compressibility in the rectilinear portion of the F–A curve. The limiting areas for F–A curves are not independent of the concentrations of spreading solutions as might be expected. The primary cause of this phenomenon in the case of high polymers appears to be a more or less coherent sponge‐ or felt‐like structure which develops at high concentration. The linear polymers, like polystyrene, become coiled up statistically and at higher concentration the coils become interlocked and produce an imperfectly spread film.

Blends of Poly(ε-caprolactone) and Intermediate Molar Mass Polystyrene as Langmuir Films at the Air/Water Interface

“…In this paper, the compatibility of amorphous intermediate molar mass PS and semicrystalline PCL mixed Langmuir films at various blend ratios are quantitatively investigated through surface pressure−area per monomer (Π− A ) isotherm studies by the Wilhelmy plate technique. Hydrophobic PS with very low surface energy does not form stable monomer-thick films at the A/W interface. − Intermediate molar mass PS samples used in this study refer to PS samples of weight average molar mass from 1.56 to at least 217 kg·mol -1 with bulk glass transition temperatures ( T g ) above the experimental temperature of 22.5 °C. Evolving biphasic morphologies of a series of mixed PCL/PS films are simultaneously observed by Brewster angle microscopy (BAM) during hysteresis experiments.…”

“…Hydrophobic PS with very low surface energy does not form stable monomer-thick films at the A/W interface. [39][40][41][42] Intermediate molar mass PS samples used in this study refer to PS samples of weight average molar mass from 1.56 to at least 217 kg‚mol -1 with bulk glass transition temperatures (T g ) above the experimental temperature of 22.5 °C. Evolving biphasic morphologies of a series of mixed PCL/ PS films are simultaneously observed by Brewster angle microscopy (BAM) during hysteresis experiments.…”

Monolayer of polystyrene monomolecular particles on a water surface studied by Langmuir-type film balance and transmission electron microscopy

“…Figure7. Dependence of x-A curves on the compression rates.Solid line: x-A curve measured by the usual compression rate, 4.4 X 104 A2 molecule"1 min"1.…”